The present invention relates generally to structural floor panels and more specifically relates to panels which are used in raised floor applications.
Raised floor systems are typically used in installations where wire cables, pipes or the like must be concealed and easily accessible. The most common application or raised floor systems is in conjunction with computer rooms. Typically, a computer room houses a plurality of computers and associated peripheral devices. These devices typically include a large number of electrical cables which must run from device to device and from device to equipment not located within the bounds of the computer room. Raised flooring systems offer a way of concealing the large number of cables while still allowing the cables to be accessed for servicing and other purposes.
Raised flooring systems essentially are comprised of a first floor which is constructed above and supported by a second floor. The first floor usually consists of a plurality of structural panel elements which are supported above the second floor by a plurality of stilt or pedestal members. These pedestal members are typically located at the corners of the panel members. Because the panel members must serve as structural support members capable of bearing the load imposed on them, their design goes beyond sheer aesthetics generally associated with tiling, and their structural integrity becomes a predominant concern.
Many floor panel designs have been disclosed for creating raised floor systems. For example, U.S. Pat. No. 4,594,833 issued to Mieyal on June 17, 1986 discloses a floor panel constructed from a honeycomb structure. Although designs of this type may be effective, they consist of many individual parts which must be assembled, thereby adding to the expense of producing this honeycomb structure.
Other raised floor designs incorporate the use of concrete as a core element. For example, U.S. Pat No. 4,067,156 issued to Downing, Jr. on Jan. 10, 1978 discloses a panel for elevated access floors in which the panel is formed of reinforced expanded lightweight concrete. Although floor panels which are constructed of concrete exhibit superior load-bearing characteristics, they are generally more expensive to produce than floor panels constructed of sheet metal and other lightweight materials, and their load-bearing capacity greatly exceeds that which is normally needed in conventional computer room installations. Their concrete core construction also has the drawbacks of being extremely heavy and difficult to maneuver.
Other panel constructions utilize the combination of concrete and sheet metal, such as U.S. Pat. No. 4,621,468 issued to Likozar on Nov. 11, 1986. This patent discloses an access floor panel which is comprised of a sheet metal pan filled with lightweight concrete material. This type of flooring system shares similar advantages and disadvantages with those of the '156 patent issued to Downing, Jr. previously discussed.
U.S. Pat. No. 4,426,824 issued to Swensen on Jan. 24, 1984 discloses an elevated floor panel formed of an upper sheet metal surface member and a lower sheet metal support member. Panels incorporating sheet metal as their primary structural component offer some advantages over the previously discussed panel designs. For example, the weight of a sheet metal panel is typically a fraction of its concrete counterpart. In addition, they are typically much cheaper to manufacture and easier to maneuver. The '824 patent issued to Swensen uses a system of integral legs formed of material which is displaced from the lower support member. These legs are formed upwardly and fastened to the upper surface member. Because each aperture includes a plurality of integral legs, each leg within each aperture must be independently welded or otherwise fastened to the upper support surface member. Each weld which must be made adds to the total cost of each panel. Additionally, since each leg stands alone, it gains no lateral support from adjacent legs in close proximity to the weld. This limits the overall strength which can be achieved in panels using this type of design.
Although the primary purpose of raised floor panels is to structurally support an applied load, they must also be easily removable and insertable. This feature is necessary because the plurality of wire and cables they conceal must often be accessed for servicing or the like. Ideally, the panels abut one another along their peripheral faces, thereby preventing any substantial lateral movement of the flooring system. Typically, however, the individual panels become wedged against each other. This wedging can be caused by slight lateral movement of the panels or may be caused by debris which is driven between adjacent panels. When two panels become wedged, they are very difficult to remove.
It is therefore a principal object of this invention to provide a raised floor panel which is of lightweight construction having superior load-bearing capacity.
Another object of the present invention is to provide a raised floor panel which is easily removed and installed.
Still another object of the present invention is to provide a raised floor panel which is inexpensive to manufacture, durable and simple in construction.